干法制备高中孔率生物质成型活性炭

Preparation of biomass-based activated carbon with high-mesoporosity by direct zinc chloride activation

以锯末为原料,氯化锌为活化剂,不添加黏结剂,采用干法混合后直接成型活化制备高中孔率生物质成型活性炭。为考察这种工艺的可行性,通过单因素实验,以亚甲基蓝吸附值为评价指标,考察了盐料比、活化温度、活化时间与成型密度对生物质成型活性炭吸附性能的影响,得出较优工艺条件为:盐料比1.0:1,活化温度950℃,活化时间为60 min,成型密度为1.4 g·cm^(-3)。在此工艺条件下制备得到的生物质成型活性炭,其亚甲基蓝吸附值为387 mg·g^(-1),BET比表面积为2104 m^2·g^(-1),平均孔径为3.11 nm,总孔容为1.63 cm^3·g^(-1),中孔孔容为1.17cm^3·g^(-1),中孔率高达71.8%,初步证明了干法制备高中孔率生物质成型活性炭工艺的可行性。

The high-mesoporosity activated carbon was prepared from sawdust by zinc chloride activation. Before activation, the zinc chloride and sawdust were mixed directly without binder or water. In order to investigate the feasibility of this process, the effects of factors such as impregnation ratio, activation temperature, activation time and the density on methylene blue adsorption properties of the activated carbon were studied. The results showed that the optimum conditions were impregnation ratio 1.0：1, activation temperature 950℃, activation time 60 min and the density 1.4 g·cm^（-3）. The activated carbon prepared under the optimized conditions had a methylene blue adsorption value of 387 mg·g^（-1）, a BET surface area of 2104 m^2·g^（-1） and the average pore diameter of 3.11 nm. The total pore volume of the activated carbon was 1.63 cm^3·g^（-1） with a mesopore volume of 1.17 cm^3·g^（-1）, yielding a high mesopore percentage of 71.8%. The results showed that the activated carbon had an excellent adsorption capacity due to its large surface area and well-developed mesopore structure, indicating the feasibility of the dry process.